This study evaluated zinc glycinate (ZG) on necrotic enteritis (NE) in chickens through two in vivo experiments and one in vitro experiment. In vivo, ZG was supplemented (study 1: 40–120 mg/kg; study 2: 100–160 mg/kg). In total, 192 (exp. 1) and 240 Cobb male birds (exp. 2) (n = 6) were studied for 28 days. ZG at 120 mg/kg significantly improved BWG by day 28 (p < 0.05), while 140 mg/kg reduced FCR (p < 0.05). Lesions were significantly reduced by 120 mg/kg (p < 0.01), and mortality was lowered by 80 mg/kg (study 1, p < 0.05) and 120 mg/kg (study 2, p < 0.01). ZG at 160 mg/kg increased IFN-γ expression in the spleen (p < 0.01), and 140 mg/kg decreased Zn/Cu SOD1 in the cecal tonsils (p < 0.05). In vitro, zinc (10–1000 µM) enhanced intestinal cell viability under Clostridium perfringens challenge. Cytotoxicity in HD-11 cells decreased significantly at concentrations ≥100 µM after 12 h (p < 0.001) and ≥10 µM after 24 h (p < 0.001), with the lowest levels observed at 100 µM (p < 0.001). We recommend increasing zinc to 120 mg/kg as ZG in poultry feed against NE infection.
Ng et al. (Wed,) studied this question.